Gauge for chaser grinding



Oct. 30, 1934. E T BYSSHE ET AL 1,979,023

GAUGE FOR CHASER GRINDING Filed April 17, 1950 fg L@ @Z f f l@ 54 23 956 4f l sz/1%, f a

Patented Oct. 30, 1934 GAUGE FOR CHASER GRINDING Ernest T. Bysshe and Robert R. Finn, Springfield, Vt., assignors to Jones & Lamson Machine Company, Springfield, Vt., a corporation of Vermont Application April 17, 1930, Serial No. 444,973

9 Claims.

Chasers for cutting screw threads are sometimes provided with means by which they can be fixed in dies in certain dennitepositions diiering from each other by predetermined successive increments. When such a chaser becomes dull and is sharpened, it is important that the amount of stock` removed in the sharpening operation be so gauged that the cutting teeth of the chaser may be correctly related to the work when the sharpened chaser is returnedl to the die.

The present invention has for its object to provide a gauge by which sharpening back to the proper extent may be facilitated. To this end the gauge comprises chaser-holding means engaging with that part of the chaser by which its position in the die` is determined, together with a micrometer gauging elementengageable with the cutting edgel of the chaser'while so held and showing the proper1` positionV to which the sharpening should A be eifected in order that the chaserA may properly engage thev work when returned to the die.

For a more complete understanding of this invention, referencevmay be had to the accompanying drawing in which Figure 1 is an end elevation of a die partly broken away and in section, this die being equipped with chasers of the tangent type.

Figures 2 and 3 are top and side elevations, respectively, of a gauge for use with a die such as is shown in Figure 1.

Figure 4 is an end elevation of the gauge. Figure 5 is a section on line 5--5 of Figure 2.

Figure 6 is a fragmentary view similar to a portion of Figure 5, but to a larger scale and showing the chaser released fromv the gauge.

Figures 7 and 8V are sections on line 7-7 and 8 8, respectively, of Figure 5. 4

Figure 9 is a section to the same scale as Figure 8, but online 9--9 of Figure 6.

' Referring to Figure 1, at 1 are shown four i chaser holders arranged on the end face of a Adie indicated generally at 2, each of these chaser holders holding a chaser 3 of the tangent type in position to operate on work extending through a central opening 4 in the die. The die and chaser holding mechanism, as shown in this figure, are identical with those shown in our application for patent Serial No. 431,498, led February 25, 1930, for Automatic die. As shown in this gure, each chaser isV provided with a serrated rear face as at 5' on adovetail portion 6. This dovetail por-v tion rides in a mating portion on a face of the corresponding chaser holder and the chaser is designedto be held by means engaging in its serrations in any of' a plurality of positions longitudinally, successively differing from each other by increments measured by the size of the serrations 5.

There is also shown in this gure one means for retaining the chasers in any of these positions. As shown, this means comprises a plug 7 seated within the socket of the holder 1 and having an outer face serrated for engagement with the serrations 5 of the chaser. This plug is slidable in the socket 8 in the chaser holder and is normally pressed outwardly into engagement with the chaser serrations as by means of the spring 9 reacting between the base of the socket and the base of the plug. This plug has a transverse opening 10 therethrough within which may extend the inner end portion of a securing and releasing member l1. This member 1l has a head portion l2 provided with a socket 13 for receiving a tool by which it may be turned and inwardly of the head portion it is threaded as at 14 to engage in a threaded opening 15 in the chaser holder. Inwardly of this threaded portion the member 1l has a shank portion 16 of reduced diameter having an enlarged head 17 at its end. This head may be extended into an opening 18 in alinement with the threaded opening in which the threaded portion 14 engages and when in this position with the shank portion 16 extending through the opening 10 of the plug, the spring 9 may press the plug 7 outwardly into chaser-engaging position. There is sufiicient looseness between a counterbored portion 19 of the plug opening and the inner end of the threaded portion 11i to permit the plug to adjust itself to the chaser serrations without binding, but insuilicient to permit the plug to be pressed inwardly enough to release its hold on the chaser serrations. By unscrewing the member ll the head 17 may be brought into the opening 10, wedging the plug '7 further into its socket sufficiently to release the chaser so that it may be withdrawn. It is thus apparent that the chaser may be held in any of a plurality of lengthwise positions, successive positions limited to diier one from the next by a denite space increment. Consequently when a chaser becomes dull and must be sharpened, it should be sharpened to an extent sumcient to bring its cutting edge into proper engagement with the work when the chaser is set over one or more of these successive increments as determined by the spacing of the serrations. In order that this may be done the gauge shown in Figures 2 to 9 has been provided.

As shown, this gauge comprises' a block 20 having along one face a dovetail slot 21 to receive the dovetail portions 6 of the Chaser in the same manner that the Chaser holder 1 receives the Chaser. This block 20 is provided with a socket 22 opening into this dovetail guideway 21 similar to the socket 8 which receives the plug 7 in the Chaser holder. A plug 23 which may be similar to the plug 7 is seated in this recess and normally pressed outwardly with its serrated outer face in engagement with the serrations of the Chaser by a spring 24. This plug 23 is also provided with a transverse perforation 25 similarl to the perforation 10 of the plug 7 and through this extends a portion of a holding and releasing member 26. This member may be identical withY the member 11 used in the die, with the exception that it is preferably provided with an eX- tension 28 at its outer end having a knurled handle portion 29 by which it may be turned in place of requiring the use of a separatey tool for this purpose. It is provided with a thre-aded portion 30 engaging a threaded opening 31 in the block 20 and terminating in an annular shoulder 32 which may engage in a counterbored portion 33 in the perforation 25 of the plug 23 and it also is provided with a shank 34 of reduced diameter provided with a head 35 at its outer end. This head 35 may ride in an opening 36 in alinement with the threaded opening 31, as shown in Figures 3, 5 and 6. Thus the Chaser may be held in any of a plurality of positions on the guide block 20, differing from each other by the same definite increments as when the Chaser is held by the die and it may be released :in the same manner by unscrewing the holding and releasing member to bring the head 35 into the perforation 25 of the retaining plug, as shown in Figure r6.

Also slidable in the dovetail guideway 21 is a dovetail portion 40 of a gauging element 41, which is shown as provided with a projection 42 at one side which may be brought into engagement with the cutting edge of a Chaser, as shown in Figure 3,'and also by a dotted line indicating Y the engaging element 42 in Figure 5. vThis element 41 is preferably held releasably on the block 20 and for this purpose it is shown as provided with a pin 44, which may pass through a perforation therethrough and into an opening 45 in the block 20, there being sulicient looseness between the pin and the opening 45 to permit the desired amount of axial movement of the gauging element 41; The end of the block 20 beneath the gauging element is shown as provided with a threaded opening for the reception of the threaded portion 51 of a micrometer screw having an enlarged portion 53 provided with micrometer graduations thereon cooperating with a Zero line as at 54 shown on a mating inclined face portion 55 of the gauging element. This micrometer screw portion -is so designed that whenthe portion 42 is in engagement with the Chaser cutting edge and the Chaser Cutting edge is so ground as to come exactly to tangency with the Work when the Chaseris inserted in the die in the same position it occupies on the block 20, the zero mark on the micrometer member 53 will register with the zero mark 54 on the gauging elementv and also the gauging lines 56 on the gauging element 41 and 57 on the block 20 will register. Ordinarily this Cutting edge should be set ahead of this point of tangency a slight amount,` this being shown by lack of registry between the two zero marks to the desired extentv as shown, for example, in Figure 2. The

Chaser should be ground back in sharpening therefore, until, when it is placed in the gauge the desired indication may be produced when the gauging element is moved into contact with the Chaser by actuation of the micrometer screw.

From the foregoing description of an embodiment of this invention it should be evident to those skilled in the art that various changes and modifications might be made without departing from the spirit or scope of this invention as dened by the appended Claims.

We claim:

1. A device of the class described Comprising means for holding a Chaser in any one of a plurality of predetermined positions said positions differing from each other by definite space increments, an element engageable with the cutting edge of said Chaser, and micrometer means for indicating the position of said element.

2. A device of the Class described comprising a supporting block, means carried by said block for engaging and holding a Chaser in any one of a plurality of denite positions differing from each otherby -denitespace increments, an element also Carried by saidvblcck` and movable toward and from the cuttingportion of a Chaser so held,

.andy micrometer means for indicating the position of said element.

3. A device of the Class described comprising a supporting block having a guideway along one face to receive a Chaser, said block having a socket communicating with said guideway, an element in said socket having a face portion formed to engage a Chaser in said guideway to restrain said Chaser from movement in said guideway and in any one of a plurality of denite positions, means for Controlling the position of said element to engage or 'release the Chaser, a gauge element slidable in said guideway toward and from thecutting portion of said Chaser, and means for indicating the position of said gaug element when engaging said Chaser. I

4. A device of the class, described comprising a supporting block having a guideway along oneV face to receive a Chaser, said block having a socket communicating with said guideway, an element in said socket having a serrated outer face for engagement in mating serrations in a Chaser insaid guidewaya spring lfor yieldingly holding said element in engagement with the Chaser, said block including means cooperating with saidv Chaser for holding sai-d yChaser in said guideway `against the pressure of said spring, a member for retaining said element in said socket actuable to retract said element to release the Chaser, and a gauging element movable said guidevvay from and toward the Cutting portion of the Chaser.

5. A device of the class described 'comprising a supporting block havinga guidevay along one face to receive a Chaser, said block having a socket communicating with said guideway, an elementin said socket having a serrated outer fa'ce for engagement in mating serrations in a Chaser in said guideway, a spring for yieldingly holding said element in engagement with the Chaser, said block including meanspooperating with said Chaser for holding said Chaser in said guideway against-the pressure of said spring, said element having a lateral perforation therethrough, and a member having a stem and a head on the end of said stem, said member being adjustable axially through said opening and positioned to -hold said element retracted to release a Chaser in said guideway when said head is in said perforation and to permit said spring to hold said element in Chaser-retaining position when said stem lies Within said perforation and said head is out therefrom.

6. A device of the class described comprising -a supporting block having a guideWay along one face to receive a Chaser, said block having a socket communicating with said guideway, yan element in said socket having a serrated outer face for engagement in mating serrations in a chaser in said guideway, a spring for yieldingly holding said element in engagement with the chaser, said block including means cooperating with said chaser for holding said -chaser in said guideway against the pressure of said spring, said block having a threaded opening leading to said socket and an opening in line with said threaded opening beyond said socket, and said element having a lateral perforation therethrough, and a member passing through said perforation and having a threaded portion engaging said threaded opening, a reduced diameter stem extending from said threaded portion, and a head on the end of ysaid stern engageable Within said alined opening, said openings being located to cause said element to be retracted to release a chaser in said guideway when said head is in said perforation and to permit said spring to hold said element in Chaser-retaining position when said stern lies Within said Iperforation and said head is out therefrom.

7. A -device of the class described comprising a block, means for holding a chaser on said block in any one of a plurality of denite positions, said block having `an undercut groove, a gauging element slidably mounted in said groove for movement toward and from the cutting portion of a Chaser held by said block, said block having a hole therein, a pin carried by said element and projecting Within said hole for limiting the sliding movement of said element, and a screw for moving said element toward gauging position and provided with micrometer position indications.

8. A device of the class described comprising a supporting block having a guideway along one face to receive a chaser, means for securing a chaser in said guideway in any one of a plurality of deiinite positions longitudinally of said guide- Way differing from each other by denite space increments, an element adjustable along said block toward and from the cutting portion of the chaser so held, and micrometer means for indicating the position of said element relative to said block.

9. A device of the class described comprising a support, means for holding a cli-aser to said support in any one of a plurality of predetermined positions, limited by definite space increments one from the next, and means for indicating the position 'of the cutting portion of a chaser so held with reference to said holding means.

ERNEST T. BYSSHE. ROBERT R. FINN. 

